U.S. patent number 7,219,720 [Application Number 10/531,182] was granted by the patent office on 2007-05-22 for flat hollow body for passing fluid therethrough, heat exchanger comprising the hollow body and process for fabricating the heat exchanger.
This patent grant is currently assigned to Showa Denko K.K.. Invention is credited to Yoshinori Katada, Naoshi Wakita.
United States Patent |
7,219,720 |
Wakita , et al. |
May 22, 2007 |
Flat hollow body for passing fluid therethrough, heat exchanger
comprising the hollow body and process for fabricating the heat
exchanger
Abstract
A fluid passing flat hollow body 2 comprises an upper and a
lower flat plate 15, 16 elongated laterally and spaced apart as
positioned one above the other, and a channel forming body 17
interposed between and brazed to the two flat plates 15, 16. The
channel forming body 17 comprises two straight side bars 18
extending laterally and arranged between the upper and lower flat
plates 15, 16 respectively at front and rear opposite side edges
thereof, an intermediate bar 19 extending laterally and disposed
between and spaced apart from the two side bars 18, two heat
transfer area increasing portions 21 each interconnecting the
intermediate bar 19 and each of the side bars 18 integrally
therewith and positioned at an intermediate portion of the height
of the bars, and end bars 22 extending forwardly or rearwardly
inward from right ends of the respective side bars 18 integrally
therewith and having respective inner ends butting on and brazed to
front and rear opposite side faces of a right end of the
intermediate bar 19. The intermediate bar 19 has a left end portion
cut out therefrom, the two heat transfer area increasing portions
21 have respective right end portions cut out therefrom, and each
of the flat plates 15, 16 has holes 13, 14 formed in a right end
portion thereof respectively on front and rear opposite sides of
the intermediate bar 19. Each of the two flat plates 15, 16 is bent
at a left end portion thereof toward the other flat plate, and the
bent portions 15a, 16a are lapped over and brazed to each
other.
Inventors: |
Wakita; Naoshi (Tochigi,
JP), Katada; Yoshinori (Tochigi, JP) |
Assignee: |
Showa Denko K.K. (Tokyo,
JP)
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Family
ID: |
32096715 |
Appl.
No.: |
10/531,182 |
Filed: |
October 9, 2003 |
PCT
Filed: |
October 09, 2003 |
PCT No.: |
PCT/JP03/12936 |
371(c)(1),(2),(4) Date: |
April 11, 2005 |
PCT
Pub. No.: |
WO2004/033978 |
PCT
Pub. Date: |
April 22, 2004 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060032251 A1 |
Feb 16, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60480745 |
Jun 24, 2003 |
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Foreign Application Priority Data
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Oct 11, 2002 [JP] |
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2002-298591 |
Feb 12, 2003 [JP] |
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2003-033057 |
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Current U.S.
Class: |
165/167; 165/153;
165/166; 29/890.039 |
Current CPC
Class: |
B23P
15/26 (20130101); F28D 1/0375 (20130101); F28D
1/0383 (20130101); F28F 3/027 (20130101); F28F
9/0221 (20130101); F28D 2021/0049 (20130101); F28F
2275/04 (20130101); F28F 2240/00 (20130101); Y10T
29/49368 (20150115); Y10T 29/49366 (20150115) |
Current International
Class: |
F28F
3/08 (20060101) |
Field of
Search: |
;165/165-167
;29/890.039,890.03 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3-221789 |
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Sep 1991 |
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JP |
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9-89477 |
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Apr 1997 |
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JP |
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2001-280883 |
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Oct 2001 |
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JP |
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98/25093 |
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Jun 1998 |
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WO |
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02/63223 |
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Aug 2002 |
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WO |
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Primary Examiner: Walberg; Teresa J.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier
& Neustadt, P.C.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is an application filed under 35 U.S.C.
.sctn.111(a) claiming the benefit pursuant to 35 U.S.C.
.sctn.119(e)(1) of the filing data of Provisional Application No.
60/480,745 filed Jun. 24, 2003 pursuant to 35 U.S.C. .sctn.111(b).
Claims
The invention claimed is:
1. A fluid passing flat hollow body comprising: an upper flat plate
and a lower flat plate elongated laterally and spaced apart as
positioned one above the other; and a channel forming body
interposed between and brazed to the upper and lower flat plates,
the channel forming body comprising two straight side bars
extending laterally and arranged between the upper and lower flat
plates respectively at front and rear opposite side edges thereof,
an intermediate bar extending laterally and disposed between and
spaced apart from the two side bars, two heat transfer area
increasing portions each interconnecting the intermediate bar and
each of the side bars integrally therewith and positioned at an
intermediate portion of the height of the bars, and plural end bars
extending forwardly or rearwardly inward from right ends of the
respective side bars integrally therewith and having respective
inner ends butting on and brazed to front and rear opposite side
faces of a right end of the intermediate bar, wherein the
intermediate bar has a left end portion cut out therefrom, the two
heat transfer area increasing portions have respective right end
portions cut out therefrom, each of the upper and lower flat plates
has holes formed in a right end portion thereof respectively on
front and rear opposite sides of the intermediate bar, the upper
and lower flat plates provide upper and lower walls, respectively,
a left end portion of each of the upper and lower flat plates is
bent toward the other flat plate, with the bent portions lapped
over and brazed to each other, to thereby provide a left wall
portion of a peripheral wall, the side bars of the channel forming
body providing respective front and rear opposite side wall
portions of the peripheral wall, the end bars of the channel
forming body providing a right wall portion of the peripheral wall,
the peripheral wall interconnects peripheral edges of the upper and
lower walls, the intermediate bar provides a partition wall
dividing the interior of the peripheral wall into front and rear
two channels extending laterally, each of the upper and lower walls
has the two holes formed in the right end portion thereof
respectively on front and rear opposite sides of the partition wall
and spaced apart transversely of the upper or lower wall for
causing the respective channels to communicate with the outside
therethrough, and the left end portion of the partition wall is cut
out to hold the two channels in communication with each other.
2. A fluid passing flat hollow body according to claim 1, wherein
each of the upper and lower flat plates is made of an aluminum
brazing sheet, and the channel forming body is made of an aluminum
extrudate.
3. A fluid passing flat hollow body according to claim 1, wherein
one of the left-end bent portions of the upper and lower flat
plates which is positioned inside has a part corresponding to each
of side bars of the channel forming body, the side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the side
bar corresponding part and the side bar, the other bent portion
which is positioned outside having a part corresponding to each
side bar of the channel forming body, the second-mentioned side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the side
bar corresponding parts of the inside and outside bent portions,
and the part of each of the left-end bent portions of the upper and
lower flat plates other than the parts thereof corresponding to the
side bars of the channel forming body has on an inner side thereof
a radius of curvature greater than the radius of curvature of the
side bar corresponding parts on the inner side thereof.
4. A fluid passing flat hollow body according to claim 3 wherein
the side bar corresponding parts of the left-end bent portions of
the upper and lower flat plates are up to 0.2 mm in radius of
curvature on the inner side thereof, and the parts of the left-end
bent portions of the upper and lower flat plates other than the
side bar corresponding parts thereof have on the inner side thereof
a radius of curvature not smaller than the thickness of the upper
and lower flat plates.
5. A fluid passing flat hollow body according to claim 3 wherein
the left-end bent portion of the upper or lower flat plate which
bent portion is positioned inside has at the part thereof other
than the side bar corresponding parts such a height that said part
of the bent portion will not interfere with the curved part of the
bent portion which is positioned outside.
6. A heat exchanger comprising fluid passing portions extending
laterally and arranged one above another in parallel at a spacing,
a spacer disposed between right ends of each pair of adjacent fluid
passing portions and brazed to the pair of fluid passing portions,
a spacer bar disposed between left ends of each pair of adjacent
fluid passing portions and brazed to the pair of fluid passing
portions, and a fin provided between and brazed to each pair of
adjacent fluid passing portions and positioned between the spacer
and the spacer bar, each of the fluid passing portions comprising a
fluid passing flat hollow body according to claim 1, the spacer
having two through holes communicating respectively with the two
holes of each of the upper and lower walls of the flat hollow
body.
7. A heat exchanger comprising fluid passing portions extending
laterally and arranged one above another in parallel at a spacing,
a spacer disposed between right ends of each pair of adjacent fluid
passing portions and brazed to the pair of fluid passing portions,
a spacer bar disposed between left ends of each pair of adjacent
fluid passing portions and brazed to the pair of fluid passing
portions, and a fin provided between and brazed to each pair of
adjacent fluid passing portions and positioned between the spacer
and the spacer bar, each of the fluid passing portions comprising a
fluid passing flat hollow body according to any one of claims 3 to
6, the spacer having two through holes communicating respectively
with the two holes of each of the upper and lower walls of the flat
hollow body.
8. An industrial machine comprising a heat exchanger according to
claim 6 and useful as an oil cooler.
9. An industrial machine comprising a heat exchanger according to
claim 6 and useful as an aftercooler.
10. An industrial machine comprising a heat exchanger according to
claim 7 and useful as an oil cooler.
11. An industrial machine comprising a heat exchanger according to
claim 7 and useful as an aftercooler.
12. A process for fabricating a heat exchanger according to claim 7
which process is characterized by: preparing channel forming body
blanks of aluminum extrudates each comprising two straight side
bars extending laterally and spaced apart forwardly or rearwardly,
an intermediate bar extending laterally and disposed between and
spaced apart from the two side bars, and two flat plate portions
each interconnecting the intermediate bar and each of the side bars
integrally therewith and positioned at an intermediate portion of
the height of the bars, pairs of upper and lower flat plates
elongated laterally, spacers each having two through holes spaced
apart forwardly or rearwardly, and spacer bars, making channel
forming bodies each by cutting out left and right end portions of
the intermediate bar of the blank, cutting out a right end portion
of each of the flat plate portions of the blank over a length equal
to the length of the cutout of the right end portion of the
intermediate bar, subjecting each flat plate portion of the blank
to press work to form a heat transfer area increasing portion, and
bending right end portions of the side bars of the blank forwardly
or rearwardly inward to cause outer ends thereof to butt on front
and rear opposite side faces of the right end of the intermediate
bar and to form end bars, bending the flat plates in each pair
toward each other at left end portions thereof to form bent
portions and forming two holes in a right end portion of each flat
plate respectively on front and rear opposite sides of the
intermediate bar, arranging a plurality of combinations one above
another in parallel at a spacing, each of the combinations
comprising the channel forming body interposed between the pair of
upper and lower flat plates, providing the spacer between right end
portions of each pair of adjacent combinations with the two through
holes in communication with the respective two holes of each of the
flat plates, providing the spacer bar between left end portions of
each pair of adjacent combinations, and further providing a fin
between each pair of adjacent combinations, as positioned between
the spacer and the spacer bar, and brazing each pair of upper and
lower flat plates to the side bars, the intermediate bar and the
end bars of the channel forming body between the pair of flat
plates, outer ends of the end bars to the intermediate bar, and the
bent portions of the pair of flat plates to each other, and further
brazing each pair of adjacent flat plates to the spacer, the spacer
bar and the fin which are interposed therebetween.
13. A process for fabricating a heat exchanger according to claim
12 wherein the flat plates are made of an aluminum brazing sheet,
the spacers, the spacer bars and channel forming body blanks are
made of aluminum extrudates, the fin is made of a thin aluminum
plate, and the brazing operation is conducted with a brazing
material melting from the flat plates.
14. A process for fabricating a heat exchanger according to claim
12 wherein one of the left-end bent portions of the upper and lower
flat plates which is positioned inside has a part corresponding to
each of side bars of the channel forming body, the side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the side
bar corresponding part and the side bar, the other bent portion
which is positioned outside having a part corresponding to each
side bar of the channel forming body, the second-mentioned side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the
second-mentioned side bar corresponding part and the side bar, and
the part of each of the left-end bent portions of the upper and
lower flat plates other than the parts thereof corresponding to the
side bars of the channel forming body has on an inner side thereof
a radius of curvature greater than the radius of curvature of the
side bar corresponding parts on the inner side thereof.
15. A process for fabricating a heat exchanger according to claim
14 wherein the side bar corresponding parts of the left-end bent
portions of the upper and lower flat plates are up to 0.2 mm in
radius of curvature on the inner side thereof, and the parts of the
left-end bent portions of the upper and lower flat plates other
than the side bar corresponding parts thereof have on the inner
side thereof a radius of curvature not smaller than the thickness
of the upper and lower flat plates.
16. A process for fabricating a heat exchanger according to claim
14 wherein the left-end bent portion of the upper or lower flat
plate which bent portion is positioned inside has at the part
thereof other than the side bar corresponding parts such a height
that said part of the bent portion will not interfere with the
curved part of the bent portion which is positioned outside.
17. A fluid passing flat hollow body comprising: an first flat
plate and a second flat plate elongated laterally and spaced apart
as positioned one above the other; and a channel forming body
interposed between the first and second flat plates, the channel
forming body comprising two side bars extending laterally and
disposed between the first and second flat plates at opposite side
edges of the first and second flat plates, an intermediate bar
extending laterally and disposed between and spaced apart from the
two side bars, two heat transfer area increasing portions
interconnecting the intermediate bar and the side bars, and plural
end bars connecting end portions of the side bars and intermediate
bar at one end of the first and second flat plates, wherein the
intermediate bar forms two channels extending laterally and has a
cut out portion communicating the two channels with each other, the
heat transfer area increasing portions have cut out portions,
respectively, adjacent to the end bars, the first and second flat
plates have holes formed adjacent to the end bars in opposite sides
of the intermediate bar and for communicating the two channels with
the outside, the side bars of the channel forming body provide side
wall portions of a peripheral wall which connects peripheral edges
of the first and second flat plates, the end bars of the channel
forming body provide a first end wall portion of the peripheral
wall, and the first and second flat plates have bent portions,
respectively, lapping over to each other and providing a second end
wall of the peripheral wall at an opposite end of the first end
wall.
Description
TECHNICAL FIELD
The present invention relates to flat hollow bodies for passing a
fluid therethrough, heat exchangers comprising such hollow bodies
for use as oil coolers, aftercoolers and radiators and the like for
industrial machines such as compressors, machine tools and
hydraulic machines, and a process for fabricating the heat
exchangers.
The upper and lower sides of FIG. 1 and the left-hand side and
right-hand side thereof will herein be referred to as "upper,"
"lower," "left" and "right," respectively. The term "front" refers
to the downstream side in the direction of flow of a
low-temperature fluid flowing between each adjacent pair of flat
hollow bodies and subjected to heat exchange with a
high-temperature fluid flowing through the hollow bodies, namely,
to the direction indicated by arrows X in FIG. 1, and FIGS. 10 to
12, and the term "rear" to the opposite direction. These terms
"upper," "lower," "left," "right," "front" and "rear" are defined
for the sake of convenience; each of the these pairs of terms,
"upper" and "lower," "left" and "right," and "front" and "rear" may
be so used that the former is replaced by the latter to mean the
opposite. Further the term "aluminum" to be used hereinafter
includes aluminum alloys in addition to pure aluminum.
BACKGROUND ART
Heat exchangers already known for use in industrial machines such
as oil cooler, aftercoolers and radiators include those comprising
fluid passing hollow portions of aluminum extending laterally and
arranged one above another in parallel at a spacing, aluminum
spacers arranged between each pair of adjacent fluid passing
portions at the left and right ends thereof and brazed to the fluid
passing portions, and a corrugated aluminum fin provided between
and brazed to each pair of adjacent fluid passing portions and
positioned between the left and right spacers, each of the fluid
passing portions comprising a flat hollow body having an upper and
a lower flat wall and a peripheral wall interconnecting the upper
and lower walls along peripheral edges thereof, each of the upper
and lower walls of the flat hollow body having a hole formed in
each of left and right end portions thereof, each of the left and
right spacers having a through hole communicating with the
corresponding holes in the upper and lower walls of the flat hollow
body, a pair of left and right headers extending vertically and
each provided by all the spacers at each of the left and right ends
of the heat exchanger and the portions of the hollow flat bodies
positioned between the spacers at the exchanger end (see the
publications of JP-A No. 2001-82891 and JP-A No. 1996-233476).
The flat hollow body comprises two flat plates arranged one above
the other at a spacing and each made of an aluminum brazing sheet
having a brazing material layer over opposite surfaces thereof, and
a channel forming body of aluminum disposed between and brazed to
the flat plates, each of the flat plates having a hole formed in
each of left and right opposite end portions thereof, the channel
forming body comprising a peripheral wall interconnecting the
peripheral edges of the two flat plates and a heat transfer area
increasing portion interconnecting lengthwise intermediate parts of
two straight portions of the peripheral wall which are positioned
respectively along the front and rear opposite side edges of the
flat plates. The two flat plates serve as the upper and lower walls
of the flat hollow body, and the peripheral wall of the channel
forming body serves as the peripheral wall of the flat hollow
body.
However, the conventional heat exchanger has the following
problems. Since each pair of adjacent flat hollow bodies have
spacers therebetween respectively at the left and right opposite
ends thereof, the exchanger has relatively great weight in its
entirety. Stated more specifically, the spacer needs to be provided
with a through hole for passing therethrough a high-temperature
fluid having a high pressure, so that the spacer peripheral wall
defining the hole must have an increased thickness, consequently
increasing the weight of the spacer and therefore the weight of the
overall heat exchanger.
Since the through hole is formed in each spacer, it is impossible
to form screw holes in the spacer for use in attaching a bracket or
boss to the spacer. The bracket or boss accordingly needs to be
fixed in position by welding through a cumbersome procedure.
Although the spacer peripheral wall defining the through hole must
be given an increased thickness if screw holes are to be formed in
the spacer for use in attaching the bracket or boss thereto, this
results in a further increase in the weight of the entire heat
exchanger.
Because the heat exchanger has the headers at the respective left
and right ends thereof, the area of the unit wherein the
high-temperature fluid and the low-temperature fluid are subjected
to heat exchange, namely, the area of the core unit, is small
relative to the overall size of the heat exchanger required for the
installation of the exchanger. This imposes limitations on the
effect to improve the heat exchange efficiency.
The high-temperature fluid flows into one of the headers and
thereafter flows through the flat hollow bodies into the other
header. In the meantime, the high-temperature fluid is subjected to
heat exchange with the low-temperature fluid flowing forward from
the rear between the pairs of adjacent hollow bodes. In this case,
the portion of high-temperature fluid flowing in the rear side
portions of the hollow bodies is efficiently cooled with the
low-temperature fluid, whereas the low-temperature fluid reaching
the front side portions of the hollow bodies is already given a
relatively high temperature and therefore less efficiently cools
the high-temperature fluid flowing through the front side portions
of the hollow bodies. Consequently, the heat exchanger is not fully
satisfactory in overall heat exchange efficiency.
An object of the present invention is to overcome the above
problems and to provide a fluid passing flat hollow body which is
usable for a heat exchanger which is smaller in weight and higher
in heat exchange efficiency than the conventional heat exchanger, a
heat exchanger comprising such fluid passing flat hollow bodies,
and a process for fabricating the heat exchanger.
DISCLOSURE OF THE INVENTION
The present invention provides a first fluid passing flat hollow
body comprising an upper and a lower flat plate elongated
laterally, a peripheral wall interconnecting peripheral edges of
the upper and lower walls, and a partition wall dividing the
interior of the wall into front and rear two channels extending
laterally, each of the upper and lower walls having two holes
formed in a right end portion thereof respectively on front and
rear opposite sides of the partition wall and spaced apart
transversely of the upper or lower wall for causing the respective
channels to communicate with the outside therethrough, a left end
portion of the partition wall being cut out to hold the two
channels in communication with each other.
When first fluid passing flat hollow bodies are used for a heat
exchanger, a fluid of high temperature is cooled to some extent
with a fluid of low temperature while flowing through the front
channels of the flat hollow bodies and is then admitted into the
rear channels, and the fluid of low temperature is heated to some
extent in rear-side portions of clearances between the adjacent
hollow bodies and thereafter reaches front-side portions of the
clearances. Accordingly, even if the fluid of low temperature
reaching the front-side portions of the clearances has a relatively
high temperature, the high-temperature fluid flowing in the front
channels still has a high temperature, differs greatly from the
low-temperature fluid in temperature and is therefore efficiently
cooled. Even if the high-temperature fluid flowing in the rear
channels has its temperature reduced relatively greatly, the
low-temperature fluid in the front-side portions of the clearances
still has a low temperature, differs greatly from the
high-temperature fluid in temperature and therefore efficiently
cools the high-temperature fluid. As a result, the device achieves
a high heat exchange efficiency.
The present invention provides a second fluid passing flat hollow
body which comprises a first flat hollow body. The second flat
hollow body comprises an upper and a lower flat plate elongated
laterally and spaced apart as positioned one above the other, and a
channel forming body interposed between and brazed to the two flat
plates, the channel forming body comprising two straight side bars
extending laterally and arranged between the upper and lower flat
plates respectively at front and rear opposite side edges thereof,
an intermediate bar extending laterally and disposed between and
spaced apart from the two side bars, two heat transfer area
increasing portions each interconnecting the intermediate bar and
each of the side bars integrally therewith and positioned at an
intermediate portion of the height of the bars, and end bars
extending forwardly or rearwardly inward from right ends of the
respective side bars integrally therewith and having respective
inner ends butting on and brazed to front and rear opposite side
faces of a right end of the intermediate bar, the intermediate bar
having a left end portion cut out therefrom, the two heat transfer
area increasing portions having respective right end portions cut
out therefrom, each of the upper and lower flat plates having holes
formed in a right end portion thereof respectively on front and
rear opposite sides of the intermediate bar, the upper and lower
flat plates providing the respective upper and lower walls, a left
end portion of each of the upper and lower two flat plates being
bent toward the other flat plate, with the bent portions lapped
over and brazed to each other, to thereby provide a left wall
portion of the peripheral wall, the side bars of the channel
forming body providing respective front and rear opposite side wall
portions of the peripheral wall, the end bars of the channel
forming body providing a right wall portion of the peripheral wall.
When this flat hollow body is used to provide a heat exchanger, the
hollow body exhibits the same advantage as the flat hollow body of
the invention already described. Since the outer ends of the end
bars of the channel forming body are brazed to the intermediate
bar, the flat hollow body is given an enhanced strength. Stated
more specifically, the right end of the intermediate bar of the
channel forming body is brazed to the portion of the spacer between
the two through holes therein, and the outer ends of the end bars
are brazed to this intermediate bar. Accordingly, even if the end
bars are subjected to a force acting rightward by the fluid flowing
through the flat hollow body, the end bars are prevented from being
damaged or broken.
The present invention provides a third fluid passing flat hollow
body which comprises a second flat hollow body described wherein
each of the upper and lower flat plates is made of an aluminum
brazing sheet, and the channel forming body is made of an aluminum
extrudate. The flat hollow body can then be further reduced in
weight and becomes easy to fabricate.
The present invention provides a fourth fluid passing flat hollow
body which comprises a second flat hollow body described wherein
one of the left-end bent portions of the upper and lower flat
plates which is positioned inside has a part corresponding to each
of side bars of the channel forming body, the side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the side
bar corresponding part and the side bar, the other bent portion
which is positioned outside having a part corresponding to each
side bar of the channel forming body, the second-mentioned side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the
second-mentioned side bar corresponding part and the side bar, and
the part of each of the left-end bent portions of the upper and
lower flat plates other than the parts thereof corresponding to the
side bars of the channel forming body has on an inner side thereof
a radius of curvature greater than the radius of curvature of the
side bar corresponding parts on the inner side thereof.
The present invention provides a fifth fluid passing flat hollow
body which comprises a fourth flat hollow body described wherein
the side bar corresponding parts of the left-end bent portions of
the upper and lower flat plates are up to 0.2 mm in radius of
curvature on the inner side thereof, and the parts of the left-end
bent portions of the upper and lower flat plates other than the
side bar corresponding parts thereof have on the inner side thereof
a radius of curvature not smaller than the thickness of the upper
and lower flat plates.
With the fourth and fifth flat hollow bodies, the left-end bent
portion of the upper or lower flat plate which is positioned inside
has a part corresponding to each of side bars of the channel
forming body, and the side bar corresponding part has on an inner
side thereof a radius of curvature permitting no clearance to be
created between the side bar corresponding part and the side bar,
e.g., a radius of curvature of up to 0.2 mm. The other bent portion
which is positioned outside has a part corresponding to each side
bar of the channel forming body, and this side bar corresponding
part has on an inner side thereof a radius of curvature permitting
no clearance to be created between the side bar corresponding
parts, e.g., a radius of curvature of up to 0.2 mm. Consequently,
the fluid is prevented from leaking from between the side bar
corresponding part of the inside bent portion and the side bar, and
from between the side bar corresponding parts of bent portions of
the upper and lower two flat plates. The part of each of the
left-end bent portions of the upper and lower flat plates other
than the parts thereof corresponding to the side bars of the
channel forming body has on an inner side thereof a radius of
curvature greater than the radius of curvature of the side bar
corresponding parts on the inner side thereof, e.g., a radius of
curvature not smaller than the thickness of the upper and lower
flat plates. Accordingly, the part other than the side bar
corresponding parts is prevented from cracking, consequently giving
the left wall portion of the flat hollow body increased pressure
resistance and improved cyclic proof stress. If the part is equal
to the side bar corresponding parts in radius of curvature on the
inner side, cracks will develop in the plate, for example,
approximately to one half the thickness of the plate from the outer
surface when the upper and lower flat plates are bent, impairing
the pressure resistance and cyclic proof stress of the left wall
portion of the hollow body and entailing the likelihood that the
bent portions will crack completely due to long use to permit
leakage of the fluid. If the side bar corresponding parts of the
left-end bent portion of the upper or lower flat plate which
portion is positioned inside and the side bar corresponding parts
of the left-end bent portion which is positioned outside are, for
example, up to 0.2 mm in radius of curvature on the inner side,
cracks will develop in the plate approximately to one half the
thickness of the plate from the outer surface when the upper and
lower plates are bent, whereas the bent portions are unlikely to
crack completely despite a long period of use because the side bar
corresponding parts of the inside bent portion are brazed to the
side bars, with the side bar corresponding parts of the outside
bent portion brazed to the inside bent portion.
The present invention provides a sixth fluid passing flat hollow
body which comprises a fourth flat hollow body described wherein
the left-end bent portion of the upper or lower flat plate which
bent portion is positioned inside has at the part thereof other
than the side bar corresponding parts such a height that said part
of the bent portion will not interfere with the curved part of the
bent portion which is positioned outside. This structure eliminates
a clearance to be otherwise created between the bent portions of
the two flat plates, consequently precluding the leakage of fluid.
If the part of the inside bent portion other than the side bar
corresponding parts has such a height as to interfere with the
curved part of the outside bent portion, a clearance will occur
between the bent portions, and the bent portions will not be
brazed, when the upper and lower flat plates are assembled in
fabricating the heat exchanger.
The present invention provides a first heat exchanger which
comprises fluid passing portions extending laterally and arranged
one above another in parallel at a spacing, a spacer disposed
between right ends of each pair of adjacent fluid passing portions
and brazed to the pair of fluid passing portions, a spacer bar
disposed between left ends of each pair of adjacent fluid passing
portions and brazed to the pair of fluid passing portions, and a
fin provided between and brazed to each pair of adjacent fluid
passing portions and positioned between the spacer and the spacer
bar, each of the fluid passing portions comprising a first fluid
passing flat hollow body described above, the spacer having two
through holes communicating respectively with the two holes of each
of the upper and lower walls of the flat hollow body.
The present invention provides a second heat exchanger which
comprises fluid passing portions extending laterally and arranged
one above another in parallel at a spacing, a spacer disposed
between right ends of each pair of adjacent fluid passing portions
and brazed to the pair of fluid passing portions, a spacer bar
disposed between left ends of each pair of adjacent fluid passing
portions and brazed to the pair of fluid passing portions, and a
fin provided between and brazed to each pair of adjacent fluid
passing portions and positioned between the spacer and the spacer
bar, each of the fluid passing portions comprising one of second to
sixth fluid passing flat hollow bodies described above, the spacer
having two through holes communicating respectively with the two
holes of each of the upper and lower walls of the flat hollow
body.
The two heat exchangers of the present invention have a spacer bar
disposed between the left end portions of each pair of adjacent
flat hollow bodies and are therefore smaller in weight than the
conventional heat exchanger wherein a spacer is disposed at the
corresponding location. The spacer bar is provided only for forming
an air passing clearance and can accordingly be smaller in size and
less heavy than the spacer. This gives smaller weight to the heat
exchanger in its entirety than conventionally. Further with the
heat exchangers described, screw bores can be formed in the spacer
bar for use in attaching a bracket or boss to the spacer bar. The
bracket or boss can be fixed in place by facilitated work. Further
in the case of the heat exchangers of the invention, the entire
exchanger except for the spacers and spacer bars serves to subject
a high-temperature fluid and a low-temperature fluid to heat
exchange, so that the area of the unit wherein the high-temperature
fluid and the low-temperature fluid are subjected to heat exchange,
namely, the area of the core unit, is greater than in the
conventional heat exchanger, relative to the overall size of the
heat exchanger required for the installation of the exchanger to
ensure improved heat exchange performance.
With the two heat exchangers described, the spacer may comprise a
single member having front and rear two through holes, or front and
rear two members each having one through hole.
The two heat exchangers described can be of the following
construction.
Each of these heat exchangers is provided at a front upper end
portion thereof with a fluid inlet in communication with the front
channels of all the flat hollow bodies and with the front through
holes of all the spacers, and has a fluid outlet at a rear lower
end portion thereof in communication with the rear channels of all
the flat hollow bodies and with the rear through holes of all the
spacers.
Each heat exchanger has a fluid inlet at a front portion of right
wall upper end thereof in communication with the front channels of
all the flat hollow bodies and with the front through holes of all
the spacers, and a fluid outlet at a rear portion of right wall
lower end thereof in communication with the rear channels of all
the flat hollow bodies and with the rear through holes of all the
spacers.
Each heat exchanger has a fluid inlet at a front portion of top
wall right end thereof in communication with the front channels of
all the flat hollow bodies and with the front through holes of all
the spacers, and a fluid outlet at a rear portion of top wall right
end thereof in communication with the rear channels of all the flat
hollow bodies and with the rear through holes of all the
spacers.
In each heat exchanger, screw bores are formed in the wall of a
spacer bar facing toward a direction opposite to the fin.
In each heat exchanger, a screw bore is formed in each of the front
and rear end faces of a spacer bar.
In each heat exchanger, a spacer bar is integrally provided with a
ridge extending over the entire length thereof and projecting
outward beyond flat hollow bodies, and screw bores are formed in
least one of the upper and lower faces of the ridge and in at least
one of the front and rear end faces thereof.
The present invention provides a process for fabricating a heat
exchanger, i.e., a second heat exchanger described above, the
process being characterized by: preparing channel forming body
blanks of aluminum extrudates each comprising two straight side
bars extending laterally and spaced apart forwardly or rearwardly,
an intermediate bar extending laterally and disposed between and
spaced apart from the two side bars, and two flat plate portions
each interconnecting the intermediate bar and each of the side bars
integrally therewith and positioned at an intermediate portion of
the height of the bars, pairs of upper and lower flat plates
elongated laterally, spacers each having two through holes spaced
apart forwardly or rearwardly, and spacer bars, making channel
forming bodies each by cutting out left and right end portions of
the intermediate bar of the blank, cutting out a right end portion
of each of the flat plate portions of the blank over a length equal
to the length of the cutout of the right end portion of the
intermediate bar, subjecting each flat plate portion of the blank
to press work to form a heat transfer area increasing portion, and
bending right end portions of the side bars of the blank forwardly
or rearwardly inward to cause outer ends thereof to butt on front
and rear opposite side faces of the right end of the intermediate
bar and to form end bars, bending the flat plates in each pair
toward each other at left end portions thereof to form bent
portions and forming two holes in a right end portion of each flat
plate respectively on front and rear opposite sides of the
intermediate bar, arranging a plurality of combinations one above
another in parallel at a spacing, each of the combinations
comprising the channel forming body interposed between the pair of
upper and lower flat plates, providing the spacer between right end
portions of each pair of adjacent combinations with the two through
holes in communication with the respective two holes of each of the
flat plates, providing the spacer bar between left end portions of
each pair of adjacent combinations, and further providing a fin
between each pair of adjacent combinations, as positioned between
the spacer and the spacer bar, and brazing each pair of upper and
lower flat plates to the side bars, the intermediate bar and the
end bars of the channel forming body between the pair of flat
plates, outer ends of the end bars to the intermediate bar, and the
bent portions of the pair of flat plates to each other, and further
brazing each pair of adjacent flat plates to the spacer, the spacer
bar and the fin which are interposed therebetween.
The process of the invention for fabricating the heat exchanger
readily provides the second heat exchanger having the foregoing
advantages.
In the heat exchanger fabricating process of the present invention,
the flat plates are made of an aluminum brazing sheet, the spacers,
the spacer bars and channel forming body blanks are made of
aluminum extrudates, the fin is made of a thin aluminum plate, and
the brazing operation is conducted with a brazing material melting
from the flat plates. The flat hollow body can then be further
reduced in weight and becomes easy to fabricate.
In the heat exchanger fabricating process of the present invention,
one of the left-end bent portions of the upper and lower flat
plates which is positioned inside has a part corresponding to each
of side bars of the channel forming body, the side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the side
bar corresponding part and the side bar, the other bent portion
which is positioned outside having a part corresponding to each
side bar of the channel forming body, the second-mentioned side bar
corresponding part having on an inner side thereof a radius of
curvature permitting no clearance to be created between the
second-mentioned side bar corresponding part and the side bar, and
the part of each of the left-end bent portions of the upper and
lower flat plates other than the parts thereof corresponding to the
side bars of the channel forming body has on an inner side thereof
a radius of curvature greater than the radius of curvature of the
side bar corresponding parts on the inner side thereof. It is then
desired that the side bar corresponding parts of the left-end bent
portions of the upper and lower flat plates be up to 0.2 mm in
radius of curvature on the inner side thereof, and that the parts
of the left-end bent portions of the upper and lower flat plates
other than the side bar corresponding parts thereof have on the
inner side thereof a radius of curvature not smaller than the
thickness of the upper and lower flat plates. In these cases, the
left-end bent portion of the upper or lower flat plate which is
positioned inside has a part corresponding to each of side bars of
the channel forming body, and the side bar corresponding part has
on an inner side thereof a radius of curvature permitting no
clearance to be created between the side bar corresponding part and
the side bar, e.g., a radius of curvature of up to 0.2 mm. The
other bent portion which is positioned outside has a part
corresponding to each side bar of the channel forming body, and
this side bar corresponding part has on an inner side thereof a
radius of curvature permitting no clearance to be created between
the side bar corresponding parts, e.g., a radius of curvature of up
to 0.2 mm. Consequently, the fluid is prevented from leaking from
between the side bar corresponding part of the inside bent portion
and the side bar, and from between the side bar corresponding parts
of bent portions of the upper and lower two flat plates. The part
of each of the left-end bent portions of the upper and lower flat
plates other than the parts thereof corresponding to the side bars
of the channel forming body has on an inner side thereof a radius
of curvature greater than the radius of curvature of the side bar
corresponding parts on the inner side thereof, e.g., a radius of
curvature not smaller than the thickness of the upper and lower
flat plates. Accordingly, the part other than the side bar
corresponding parts is prevented from cracking, consequently giving
the left wall portion of the flat hollow body increased pressure
resistance and improved cyclic proof stress.
In the heat exchanger fabricating process of the present invention,
the left-end bent portion of the upper or lower flat plate which
bent portion is positioned inside may have at the part thereof
other than the side bar corresponding parts such a height that said
part of the bent portion will not interfere with the curved part of
the bent portion which is positioned outside. Thus, the part of the
inside left-end bent portion of the upper or lower flat plate other
than the side bar corresponding parts has a height not permitting
this part to interfere with the curved part of the outside bend
portion. This eliminates a clearance to be otherwise created
between the bent portions of the two flat plates, consequently
precluding the leakage of fluid. If the part of the inside bent
portion other than the side bar corresponding parts has such a
height as to interfere with the curved part of the outside bent
portion, a clearance will occur between the bent portions, and the
bent portions will not be brazed, when the upper and lower flat
plates are assembled in fabricating the heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the overall construction of an
oil cooler wherein fluid passing flat hollow bodies of the
invention are used.
FIG. 2 is an exploded perspective view showing a portion of the oil
cooler of FIG. 1.
FIG. 3 is a perspective view partly broken away and showing the
fluid passing flat hollow body of the oil cooler of FIG. 1 with
heat transfer area increasing portions omitted.
FIG. 4 includes views in vertical section and showing left end
portions of the flat hollow body of the same on an enlarged
scale.
FIG. 5 is a fragmentary exploded perspective view showing the flat
hollow body of the oil cooler of FIG. 1, spacer bars at opposite
sides thereof and left end portions of fins.
FIG. 6 is a fragmentary perspective view showing the same portions
as FIG. 5.
FIG. 7 is a view in horizontal section and showing a portion of a
channel forming body of the flat hollow body on an enlarged
scale.
FIG. 8 includes fragmentary perspective views of a right end
portion of the channel forming body to show a process for
fabricating the body.
FIG. 9 includes fragmentary perspective views of a left end portion
of the channel forming body to show the process for fabricating the
body.
FIG. 10 is a diagram showing a flow of oil in the oil cooler of
FIG. 1.
FIG. 11 is a diagram showing a flow of oil in another embodiment of
oil cooler wherein fluid passing flat hollow bodies of the
invention are used.
FIG. 12 is a diagram showing a flow of oil in another embodiment of
oil cooler wherein fluid passing flat hollow bodies of the
invention are used.
FIG. 13 is a diagram corresponding to FIG. 6 and showing a
modification of the spacer bar, in which the bracket and the screws
are not illustrated.
FIG. 14 is a diagram corresponding to FIG. 6 and showing another
modification of the space bar, in which the bracket and the screws
are not illustrated.
BEST MODE OF CARRYING OUT THE INVENTION
Embodiments of the invention will be described below with reference
to the drawings.
FIG. 1 shows the overall construction of a heat exchanger wherein
fluid passing flat hollow bodies of the invention are used, and
FIGS. 2 to 7 shows the constructions of essential portions of the
exchanger. FIGS. 8 and 9 further show a process for fabricating a
channel forming body of the flat hollow body, and FIG. 10 shows a
flow of high-temperature fluid in the heat exchanger shown in FIG.
1. Throughout the drawings, like parts are designated by like
reference numerals.
The present embodiment is a heat exchanger adapted for use as the
oil cooler of a compressor. Examples of such compressors are load
compressors, compressors for use in gas turbines, compressors
useful for brakes for railroad vehicles, etc.
FIG. 1 shows an oil cooler 1, which comprises flat hollow bodies 2
of aluminum extending laterally and arranged one above another in
parallel at a spacing for passing therethrough a high-temperature
oil, a spacer 3 of aluminum extrudate disposed between right end
portions of each pair of vertically adjacent flat hollow bodies 2
and brazed to the flat hollow bodies, a spacer bar 4 of aluminum
extrudate extending forward or rearward, disposed between left end
portions of each pair of vertically adjacent flat hollow bodies 2
and brazed to the flat hollow bodies, and an corrugated aluminum
fin 6 provided in an air passing clearance 5 between each pair of
adjacent flat hollow bodies 2, positioned between the spacer 3 and
the spacer bar 4 and brazed to the hollow bodies 2.
Arranged above the flat hollow body 2 at the upper end of the oil
cooler 1 and below the flat hollow body 2 at the lower end thereof
and spaced apart from these hollow bodies are respective aluminum
side plates 7 having the same shape and size as the flat hollow
body 2 when seen from above. A spacer 3 of aluminum extrudate is
provided also between the right end of each of the flat hollow
bodies 2 at the upper and lower ends and the right end of the side
plate 7 adjacent to the hollow body and is brazed to the hollow
body 2 and the side plate 7. A spacer bar 4 of aluminum extrudate
is provided also between the left end of each of the flat hollow
bodies 2 at the upper and lower ends and the left end of the side
plate 7 adjacent to the hollow body and is brazed to the hollow
body 2 and the side plate 7. An air passing clearance 5 is formed
also between each of the flat hollow bodies 2 at the upper and
lower ends and the side plate 7 adjacent thereto, and a corrugated
aluminum fin 5 is provided also in the clearance 5 and brazed to
the hollow body 2 and the side plate 7. The side plate 7 comprises
an aluminum brazing sheet having a brazing material layer over one
surface thereof having the spacer 3, spacer bar 4 and corrugated
fin 6 brazed thereto.
With reference to FIGS. 2 and 3, the flat hollow body 2 comprises
an upper and a lower flat plate 8 elongated laterally, a peripheral
wall 9 interconnecting the peripheral edges of the upper and lower
walls 8, and a partition wall 12 dividing the interior of the wall
9 into front and rear two channels 10, 11 extending laterally. Each
of the upper and lower walls 8 has two holes 13, 14 formed in a
right end portion thereof respectively on the front and rear
opposite sides of the partition wall 12 and spaced apart
transversely of the wall 8 for causing the respective channels 10,
11 to communicate with the outside therethrough. A left end portion
of the partition wall 12 is cut out to hold the two channels 10, 11
in communication with each other as indicated at 20. The flat
hollow body 2 comprises two rectangular flat plates 15, 16
elongated laterally and arranged one above the other at a spacing
and each made of an aluminum brazing sheet having a brazing
material layer over opposite surfaces thereof, and a channel
forming body 17 of aluminum extrudate and disposed between and
brazed to the upper and lower flat plates 15, 16.
Each of the flat plates 15, 16 has holes 13, 14 formed in
respective front and rear side parts of a right end portion
thereof. A left end portion of each of the flat plates 15, 16 is
bent toward a left end portion of the other, that is, the upper
flat plate 15 is bent downward, and the lower flat plate 16 is bent
upward, and these bent portions 15a, 16a are lapped over and brazed
to each other (see FIGS. 4 to 6). The two flat plates 15, 16
provide the upper and lower walls 8, and the bent portions 15a, 16a
of the flat plates 15, 16 provide a left wall portion 9a.
The channel forming body 17 comprises two straight side bars 18
extending laterally and arranged between the upper and lower flat
plates 15, 16 respectively at the front and rear opposite side
edges thereof, an intermediate bar 19 extending laterally and
disposed between and spaced apart from the two side bars 18, two
heat transfer area increasing portions 21 each interconnecting the
intermediate bar 19 and each of the side bars 18 integrally
therewith and positioned at an intermediate portion of the height
of the bars, and end bars 22 extending forwardly or rearwardly
inward from the right ends of the respective side bars 18
integrally therewith and having respective inner ends butting on
and brazed to the front and rear opposite side faces of the right
end of the intermediate bar 19 (see FIG. 7). The two side bars 18,
intermediate bar 19 and end bars 22 are brazed to the upper and
lower flat plates 15, 16. The intermediate bar 19 has a right end
portion brazed to each of the flat plates 15, 16 at the portion
thereof between the holes 13, 14. The intermediate bar 19 has a
left end portion cut out therefrom over a predetermined length so
as to provide the communication portion 20. Each of the heat
transfer area increasing portions 21 has a right end portion cut
out therefrom over a predetermined length so as to form a hole
matching with the holes 13 or 14 of the flat plates 15, 16. The
side bars 18 of the channel forming body 17 provide the front and
rear opposite side wall portions 9b of the peripheral wall 9, and
the end bars 22 of the body 17 provide the right wall portion 9c of
the peripheral wall 9.
The heat transfer area increasing portion 21 comprises a plurality
of wavy strips 23 each including upwardly projecting bent parts 23a
and downwardly projecting bent parts 23b alternately arranged
laterally and horizontal parts 23c interconnecting these parts 23a,
23b, the wavy strips 23 being arranged in parallel transversely of
the channel forming body 17 and connected to one another by the
horizontal parts 23c. With the strips 23 of the increasing portion
21, the pair of upward bent parts 23a which are adjacent
transversely of the body 17, as well as the pair of downward bent
parts 23b which are similarly adjacent, are positioned as shifted
from each other laterally. In the increasing portion 21, there is
the horizontal part 23c between the pair of upward bent part 23a
and the downward bent part 23b of each wavy strip 23 which are
laterally adjacent, and the pair of strips 23 which are adjacent in
the transverse direction are connected to each other by horizontal
parts 23c, whereas the horizontal parts 23c need not always be
provided. In this case, the portion where the upward bent part 23a
extends into the downward bent part 23b in one of adjacent strips
23 intersects like portion of the other strip 23, so that the
adjacent strips 23 are joined into an integral piece at such
portions.
The channel forming body 17 is fabricated in the manner shown in
FIGS. 8 and 9. For preparing the channel forming body, a blank of
aluminum extrudate is produced which comprises two straight side
bars 18 extending laterally and spaced apart transversely of the
blank, an intermediate bar 19 extending laterally and disposed
between and spaced apart from the two side bars 18, and two flat
plate portions 21 each interconnecting the intermediate bar 19 and
each of the side bars 18 integrally therewith and positioned at an
intermediate portion of the height of the bars [see FIGS. 8(a) and
9(a)]. The intermediate bar 19 is then cut out at left and right
opposite end portions thereof over a predetermined length, and a
right end portion of each of the flat plate portions 24 is cut out
over a length greater than the length of the cutout of the right
end portion of the bar 19 [see FIGS. 8(b) and 9(b)]. Subsequently,
each flat plate portion 24 is subjected to press work to form a
heat transfer area increasing portion 21 [see FIGS. 8(c) and 9(c)].
The right end portions of the side bars 18 are thereafter bent
forwardly or rearwardly inward to cause the outer ends thereof to
butt on the front and rear opposite side faces of the right end of
the intermediate bar 19 [see FIG. 8(d)], and the outer ends of the
bar 19 are brazed to the bar 19 to form two end bars 22.
Incidentally, the outer ends of the end bars 22 are brazed to the
intermediate bar 19 with a molten brazing material melted from the
flat plates 15, 16 when the heat exchanger 1 to be described later
is fabricated.
With reference to FIG. 4, one of the bent portions 15a, 16a of the
upper and lower flat plates 15, 16 which is positioned inside,
i.e., the bent portion 16a of the lower flat plate 16, has a part
16b positioned at each of the front and rear ends thereof,
corresponding to the side bar 18 of the channel forming body 17 and
having a radius R1 of curvature on the inner side thereof. The
radius R1 of curvature permits no clearance to be created between
the side bar corresponding part 16b and the side bar 18. For
example, the radius R1 is up to 0.2 mm. The other bent portion
which is positioned outside, i.e., the bent portion 15a of the
upper flat plate 15, has a part 15b positioned at each of the front
and rear ends thereof, corresponding to the side bar 18 of the
channel forming body 17 and having a radius r1 of curvature on the
inner side thereof. The radius r1 of curvature permits no clearance
to be created between the side bar corresponding parts 15b, 16b.
For example, the radius r1 is up to 0.2 mm. The parts 15c, 16c of
the bent portions 15a, 16a of the upper and lower flat plates 15,
16 other than the side bar corresponding parts 15b, 16b have on the
inner side thereof a radius r2 or R2 of curvature greater than the
radius r1 or R1 of curvature of the side bar corresponding parts
15b, 16b on the inner side thereof and not smaller than the
thickness of the upper and lower flat plates 15, 16. One of the
bent portions 15a, 16a of the upper and lower flat plates 15, 16
which is positioned inside, i.e., the bent portion 16a of the lower
flat plate 16, has at the part 16c thereof other than the side bar
corresponding parts 16b a height H smaller than the height h of a
part of the bent portion positioned outside, i.e., of the part 15c
of the bent portion 15a of the upper flat plate 15 other than the
side bar corresponding parts 15b thereof, the height H being such
that the part 16c will not interfere with the curved part 15d of
the bent portion 15a of the upper flat plate 15. According to the
present embodiment, the bent portion 16a of the lower flat plate 16
is positioned inside, with the bent portion 15a of the upper flat
plate 15 positioned outside, whereas the bent portion 15a of the
upper flat plate 15 may conversely be positioned inwardly of the
bent portion 16a of the lower flat plate 16. In this case, the bent
portion 15a and the bent portion 16a are in opposite relationship
to the above with respect to the dimensions.
With reference to FIG. 2, the spacer 3 has vertical through holes
26, 27 communicating with the respective two holes 13, 14 of the
upper and lower walls 8 of the flat hollow body 2 and in register
with the respective holes 13, 14 when seen from above. The spacer 3
disposed between the flat hollow body 2 at each of the upper and
lower ends of the oil cooler 1 and the side plate 7 adjacent
thereto has the end openings of its through holes 16, 17 closed
with the side plate 7.
An oil inlet pipe 28 of aluminum is joined by brazing to the front
wall of the spacer 3 which is disposed between the flat hollow body
2 at the upper end and the top side plate 7 so as to communicate
with the interior of the front through hole 26 of the spacer. An
oil outlet pipe 29 of aluminum is joined by brazing to the rear
wall of the spacer 3 which is disposed between the flat hollow body
2 at the lower end and the bottom side plate 7 so as to communicate
with the interior of the rear through hole 27 of the spacer. Thus,
the oil inlet pipe 28 (fluid inlet) is provided at a front upper
end portion of the oil cooler 1 so as to communicate with the front
channels 10 of all the flat hollow bodies 2, and the front through
holes 26 of all the spacers 3, and the oil outlet pipe 29 (fluid
outlet) is provided at a rear lower end portion of the oil cooler 1
so as to communicate with the rear channels 11 of all the flat
hollow bodies 2 and the rear through holes 27 of all the spacers 3.
An inlet-side header 31 is provided by the front parts of right end
portions of all the flat hollow bodies 2 and the front portions of
all the spacers 3, and the inlet-side header 31 causes right ends
of the front channels 10 of all the flat hollow bodies 2 to
communicate with the front through holes 26 of all the spacers 3
through the front holes 13 of the upper and lower walls 8. An
outlet-side header 32 is provided by the rear parts of right end
portions of all the flat hollow bodies 2 and the rear portions of
all the spacers 3, and the outlet-side header 32 causes right ends
of the rear channels 11 of all the flat hollow bodies 2 to
communicate with the rear through holes 27 of all the spacers 3
through the rear holes 14 of the upper and lower walls 8.
With reference to FIGS. 6 and 7, two adjacent spacer bars 4
included in the spacer bars 4 are provided in each of the left side
walls thereof with one screw bore 34 for use in attaching a bracket
33 or boss to both the spacer bars 4 with screws 35.
The oil cooler 1 is fabricated by arranging flat plates 15, 16 made
of aluminum brazing sheet, channel forming bodies 17 of aluminum
extrudates, spacers 3, spacer bars 4, corrugated fins 6 and side
plates 7 of aluminum brazing sheet in a specified order in
superposed layers, fitting an oil inlet pipe 28 and an oil outlet
pipe 29 to the assembly, tacking the resulting assembly by suitable
means, and brazing the assembly collectively. Stated more
specifically, the oil cooler 1 is fabricated by arranging a
plurality of combinations one above another in parallel at a
spacing, each of the combinations comprising an upper and a lower
flat plate 15, 16 and a channel forming body 17 disposed between
the flat plates, placing two side plates 7 respectively above the
combination at the upper end and below the combination at the lower
end, arranging a spacer 3, a spacer bar 4 and a corrugated fin 6
between each pair of adjacent combinations, as well as between the
combination at each of the upper and lower ends and the side plate
adjacent thereto, fitting an oil inlet pipe 28 and an oil outlet
pipe 29 to the assembly, tacking the resulting assembly by suitable
means, and collectively brazing the assembly. At this time, molten
brazing material melting from the flat plates 15, 16 is used for
brazing the flat plates 15, 16 to the channel forming bodies 17,
spacers 3, spacer bars 4 and corrugated fins 6 and brazing the
outer ends of the end bars 22 to the intermediate bars 19.
Incidentally, the spacers 3 are arranged, with the two vertical
through holes 26, 27 of each spacer in register with the respective
two holes 13, 14 of each of the flat plates 15, 16. The oil inlet
pipe 28 and the outlet pipe 29 may be joined to the corresponding
spacers 3 separately by welding.
With the oil cooler 1 thus constructed, an oil of high temperature
is admitted into the inlet-side header 31 through the oil inlet
pipe 28, then dividedly flows into all the flat hollow bodies 2 to
flow through the front channels 10 thereof leftward, further flows
into the rear channels 11 through the communication portions 20,
flows through the rear channels 11 rightward into the outlet-side
header 32 and flows out of the oil outlet pipe 29 as indicated by
an arrow Y in FIG. 10. While flowing through the front channels 10
and rear channels 11 of all the flat hollow bodies 2, the oil is
subjected to heat exchange with air of low temperature flowing
through the air passing clearances 5 in a direction indicated by an
arrow X in FIG. 10 and thereby cooled. Stated more specifically,
the oil of high temperature is cooled to some extent with the air
while flowing through the front channels 10 of the flat hollow
bodies 2 and is then admitted into the rear channels 11, and the
air of low temperature is heated to some extent in the rear-side
portions of the air passing clearances 5 and thereafter reaches the
front-side portions of the clearances 5. Accordingly, even if the
air reaching the front-side portions of the clearances 5 has a
relatively high temperature, the oil flowing in the front channels
10 has a high temperature, differs greatly from the air in
temperature and is therefore efficiently cooled. Even if the oil
flowing in the rear channels 11 has its temperature reduced
relatively greatly, the air in the front-side portions of the
clearances 5 has a low temperature, differs greatly from the oil in
temperature and therefore efficiently cools the oil. As a result,
the oil cooler achieves a high heat exchange efficiency.
According to the foregoing embodiment, the heat exchanger of the
invention is adapted for use as an oil cooler, whereas the heat
exchanger is not limited to this use but may be used as an
aftercooler or radiator for industrial machines such as load
compressors, gas turbine compressors and compressors for railroad
vehicles.
The heat exchanger of the invention is further useful as an oil
cooler for hydraulic devices for cranes, deck cranes, crane trucks
and power shovels, machine tools and like industrial machines.
FIGS. 11 and 12 show other embodiments of oil coolers. In the case
of the oil cooler 1 shown in FIG. 11, an oil inlet pipe 28 of
aluminum is joined by brazing to a front portion of the right wall
of the spacer 3 which is disposed between the flat hollow body 2 at
the upper end and the top side plate 7 so as to communicate with
the interior of the front through hole 26 of the spacer. An oil
outlet pipe 29 of aluminum is joined by brazing to a rear portion
of the right wall of the spacer 3 which is disposed between the
flat hollow body 2 at the lower end and the bottom side plate 7 so
as to communicate with the interior of the rear through hole 27 of
the spacer. Thus, the oil inlet pipe 28 (fluid inlet) is provided
at a front part of right wall upper end portion of the oil cooler 1
so as to communicate with the front channels 10 of all the flat
hollow bodies 2 and the front through holes 26 of all the spacers
3, and the oil outlet pipe 29 (fluid outlet) is provided at a rear
part of right wall lower end portion of the oil cooler 1 so as to
communicate with the rear channels 11 of all the flat hollow bodies
2 and the rear through holes 27 of all the spacers 3.
In the case of the oil cooler 1 shown in FIG. 12, an oil inlet pipe
28 of aluminum is joined by brazing to a front portion of right end
portion of the top side plate 7 so as to communicate with the
interior of the front through hole 26 of the spacer 3 at the upper
end, and an oil outlet pipe 29 of aluminum is joined by brazing to
a rear portion of right end portion of the top side plate 7 so as
to communicate with the interior of the rear through hole 27 of the
spacer 3 at the upper end. Thus, the oil inlet pipe 28 (fluid
inlet) is provided at a front part of top wall right end portion of
the oil cooler 1 so as to communicate with the front channels 10 of
all the flat hollow bodies 2 and the front through holes 26 of all
the spacers 3, and the oil outlet pipe 29 (fluid outlet) is
provided at a rear part of top wall right end portion of the oil
cooler 1 so as to communicate with the rear channels 11 of all the
flat hollow bodies 2 and the rear through holes 27 of all the
spacers 3.
Incidentally, the oil flows through the oil coolers shown in FIGS.
11 and 12 in the same manner as illustrated in FIG. 10.
FIGS. 13 and 14 show modifications of spacer bar 4.
FIG. 13 shows a spacer bar 40 integrally provided with a ridge 41
extending over the entire length thereof and projecting outward
beyond flat hollow bodies 2. Screw bores 42 for use in attaching a
bracket or boss to the spacer bar are formed in the upper and lower
faces of the ridge 41 and in opposite end faces thereof.
FIG. 14 shows a spacer bar 45 having two screw bores 46 formed in
the wall thereof facing toward a direction opposite to the
corrugated fin 6 for use in attaching a bracket or boss to the
spacer bar.
INDUSTRIAL APPLICABILITY
The invention provides a fluid passing flat hollow body which is
suitable for passing a fluid of high temperature through heat
exchangers, such as oil cooler, aftercoolers and 1s radiators, for
compressors, machine tools, hydraulic devices and like industrial
machines.
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